It depends on what you think probability is, but even then the answer is probably (heh!) no.
Nothing in the mathematical theory of probability requires that all events have probabilities. Probability theory simply imposes coherence conditions on any probability assignments there may be. And the mathematical theory of probability doesn't tell us what probability is but only what its formal properties are.
Some believe that there are objective probabilities—that if we specify our probability question appropriately, then there may be an answer to the question independent of what anyone thinks. For example: someone might think that if a quantum system has been prepared in a certain way, then the probability that a measurement interaction will have a certain result is, say, 1/3 regardless of what anyone thinks. This may or may not be right, though it still leaves us in the dark about what exactly this probability is. Is it a propensity or tendency of some sort? Is it a disguised way of talking about...

Let's suppose that the machine is my computer and I'm using the function =TRUNC(100*RAND(),0). Then as I put the function in more and more cells, I'll get a list of integers between 0 and 100 that pass various tests for randomness. Let's suppose that the fifth integer on the list is 12. Is there a reason for that?
There is, at least superficially. The function =TRUNC(100*RAND(),0) works by performing various well-defined mathematical operations on an input. The input is the time when you hit "ENTER," according to the computer's clock. Given that input and the cell, the output is determined. Put another way, if two computers ran the program starting at the same time according to their clocks, they would give the same output. So there's an explanation for why the fifth cell ends up containing 12 rather than some other integer. It's a matter of the input and the program.
You might protest that this isn't truly random. If it were, two computers with the same input wouldn't produce the same supposedly ...

I guess I'd have to disagree with the idea that "all of philosophy and logic point to a reason or cause for everything." There's certainly no argument from logic as such; it's perfectly consistent to say that some events are genuinely random. Some philosophers have held that there's a reason (not necessarily a cause in the physical sense, BTW) for everything, but the arguments are not very good.
On the other hand... quantum mechanics is a remarkably well-confirmed physical theory that, at least as standardly interpreted, gives us excellent reason to think that some things happen one way rather than another with no reason or cause for which way they turned out.
An example: suppose we send a photon (a quantum of light) through a polarizing filter pointed in the vertical direction. We let the photon travel to a second polarizing filter, oriented at 45 degrees to the vertical. Quantum theory as usually understood says that there's a 50% chance that the photon will pass this filter and a 50% chance that it...

What you say about the individual problems is right: if I get a point for each right answer, then each time someone comes to the site, the best strategy is to guess that it's a man. (At least this is right if knowing the sex of an individual customer doesn't help predict whether s/he will visit the site or not.) This is the best strategy because if each individual visit is like a random selection of a customer from the population, the chance is greater that the selected customer will be a man. The analogy with seawater is problematic. After all, if I pick one customer, that customer won't be 55% male and 45% female. The salinity of small samples of seawater closely approximates the salinity of the sea (unless we get down to really small samples of a few molecules, and then your principle breaks down.) The make-up of a small sample from a population may depart markedly from the make-up of the populations. What's interesting is that once our samples get to be of even a moderate size, things...

Games typically involve a blend of things that a player can control and things s/he can't. A golfer can work on her backswing; she can't do anything about the moment-by-moment shifts in the wind and the fine-grained condition of the greens. Things like the winds and the lay of the greens or the outcome of a dice-roll are what we might call externalities. It's not that they have no explanations and it's certainly not that they have no bearing on who wins and who loses. But the players don't deserve any blame or credit for how they turned out. In that sense, they're matters of luck. Depending on the game, skilled players may have ways of compensating for them to some extent, but they can produce advantages and disadvantages that are outside the players' control. With that in mind, I don't take Kahneman's appeal to "luck" to be an explanation. An explanation would call for specifics about conditions and causes, and the mere appeal to luck doesn't provide any of those. I take the appeal to luck to be a...

Statistics could give evidence that something about one of the casinos makes it more likely that your gambler will win there. Feng shui could be the explanation, though it would be a funny sort of feng shui that only worked for some of the gamblers, and so if it is feng shui, the casino may not be in business long! The more general question is whether there could be serious evidence that the gambler is more likely to win in one casino than the other, and the answer to that is yes. It might be feng shui, but other explanations, weird and mundane, would also be possible. (Maybe he's an unwitting participant in a psychology experiment; and the experimenters load the dice in his favor in one of the casinos.) Careful observation and experiment might even hone in on the explanation, if there really is a stable phenomenon to be explained. As for the pragmatic question, why not? If the evidence suggests that he's more likely to win in one casino than the other, he could go with the evidence without...

Right, as Silver himself would be the first to agree. However, we might want to put it a bit differently. The projections could all be mistaken, but not because his methods or premises were incorrect. Here's a way to see the general point. Suppose we consider 20 possible independent events, and suppose that for each, the "correct" probability that the event will happen is 95%. (I use shudder quotes because there's an interesting dispute about just what "correctness" comes to for probability claims, but it's a debate we can set aside here.) Then for each individual event, it would be reasonable to project that it would occur. But given the assumption that the events are independent, the probability is over 64% that at least one of the events won't occur, and there's a finite but tiny probability (about 1 divided by 10 26 ) that none of the events will occur. So it's possible that all the projections could be reasonable and all the probabilities that ground them "correct," and yet for some or...

Suppose you and I are in the same room and we're bored. We start flipping coins. I flip twice; so do you. I get "Heads; Tails," so do you. Sounds like a meaningless coincidence to me. In fact, it would take a lot of argument to make the case that it was anything other than meaningless. Surely what's just been described is possible, and so meaningless coincidences are possible. But surely it's also the sort of thing that's actually happened countless times, and so meaningless coincidences are more than just possible. The more interesting question is whether anything has purpose or significance apart from the purpose or significance that creatures like us give it. Put another way, the question is whether there's any significance inherent in the universe itself. Many religious believers would say yes, though they would trace the meaning back to the intentions of God. Carl Jung, the Swiss psychologist, believed in meaningful coincidences that he called "synchronicity." His account of them (as I...

What we're trying to get to is the probability, given all the evidence, that A is guilty. Let H be the hypothesis that A is guilty. You're supposing that our initial probability for H is 5%, i.e., .p(H) = .05. Then we get a piece of evidence – call it E – and the probability of E assuming that H is false is 10%, i.e., p(E/not-H) = .1. Your question: in light of E, how likely is H? What's p(H/E)? We can't tell. We need another number: p(E/H). We need to know how likely the evidence is if A is guilty. And we can't infer that from p(E/not-H). Why not? Well, suppose the evidence is that the Oracle picked A's name out of a hat with 10 names, only one of which was A's. The chance of that if A is not guilty is 10%, but so is the chance if A is guilty (assuming Oracles don't really have special powers.) iI this case, the "evidence" is actually irrelevant. The crucial question is this: what's the ratio of p(E/H) to p(E/not-H)? Intuitively, does H do a good job of explaining E? And knowing only one...